smh20502

My Feedback: (1)

Can anyone give me a proper setup sequence? I can't get my FX 91 to start. the engine is new to me but used, I know the guy and it ran for him well...unfortunately the engine had to sit for a wile, about a year, and while sitting various people turned screws, mixture etc. How can I get this thing started? Anyone have a place to start from zero. Not as if from new in the box, but if the engine was completely disassembled, what would be the steps on setting all screw adjustment positions, starting techniques etc.

I'm still a newbie on nitro, gas....not too much of a problem, electric zero issues. In fact, I prefer electric...simply setup the esc and go. But this nitro engine, just won't start. How long should the glow plug igniter be left on before turning the prop? The muffler will fill with nitro, so there is not clogging in the lines or carb.

smh20502

My Feedback: (1)

the plug is new #8...engine mounted at about 130 Deg.

Bax

My Feedback: (11)

You can download the instructions from:

http://www.osengines.com/manuals/index.html

smh20502

My Feedback: (1)

that doesn't help....for example. On the mixture control screw on the carb. the manual indicates that for realignment, screw in the mixture control valve until it bottoms out. The valve doesn't bottom out...it will just turn past the threads and then keep spinning.

smh20502

My Feedback: (1)

Found the mixture valve issue....throttle was open when screwing in. Followed the starting procedures and realignment as I had before (already had the manual) and still nothing. I've pulled almost a full tank and nothing, not even a sputter. Does the mounting angle make a difference? The engine is mounted at about 130deg placing the carb facing at a downward angle.

smh20502

My Feedback: (1)

engine running....problem was that my cranial cavity was in direct connection to rectal cavity. (glow igniter wasn't producing enough energy to get the glow plug hot enough to make the engine turn)

Now running I'm having a problem with smoothing the idle out and getting rid of the 4stroke sound. Also, as I start getting past half throttle it starts to get sluggish....

DirtTorpedo

OK.. need some questions answered...


What Prop and Exhaust are you running??

Is the center of the tank inline with the spraybar on the carb?

Can you see air bubbles in the line between the needle valve and the carb when the engine is running...

New glowplug?

What does the glowplug look like when you pull it out of the engine??

Is the needle valve housing part of the backplate, or is it on a standoff??



The sluggishness and bad idle could be caused by a few things, but need more info to start.

smh20502

My Feedback: (1)

The prop I'm using is a 14x8 Master Airscrew.

The exhaust is the stock E-4020 muffler

The needle valve assembly is held on with a chrome bracket on the back plate

there were no air bubbles from what I could see in the line but I'll look again today. ...the temp has been on cold side so that may be an issue as well.

the glow plug is new as to how it looks... I'm still a little too new to glow engines to have a good base. If I had to comment...no burning or carbonizing, a little residue but it can be wiped off easily.

as to the mounting....the engine sits at about 130deg like the one pictured in the below link (last posting) http://www.rcuniverse.com/forum/m_43...13/key_/tm.htm

the fuel tank location can be seen in the same series of pictures.

Judging from what I've read here, it appears to be running rich.

Bax

My Feedback: (11)

OK, the first thing to do is to mount the engine upright on a test stand and get it all properly set up. You must have the engine properly broken-in before you try to run it with the cylinder head downward. Downward at an angle is better than straight down, but it can still cause difficulties. Once the engine is properly broken-in and tuned in the upright position, you can then mount it any way you want and get it to run with few difficulties.

When an engine has the cylinder pointed more than 45-degrees down from horizontal, it tends to accumulate fuel in the glow plug at mid-to-low throttle settings. That can make idle and acceleration erratic and even impossible at times. Proper tuning can eliminate some of these tendencies, however some engines just never can run well inverted, so you'll need a glow plug battery that turns on below 1/3-throttle or so to light the glow plug. Even two identical engines can run differently-enough that one will need the battery and one will not.


Before the idle can be properly-set, you have to get the full-throttle mixture properly-set. When the O.S. .91 FX is properly-tuned, the high-speed needle valve will be about 1-1/2 to 1-3/4 turns out from closed when just rich of peak RPM. Select a propeller that will allow the engine to turn in the high-11,000's, and you'll do just fine, and actually get more gross power. O.S. recommends rather large propellers for noise reduction because many flying fields in Japan have rather strict noise limitations. You can go down to a 13 x 8 or 10 prop quite easily.